Aspinall Unit operations update: Streamflow forecast for April-July = 87% of average

Gunnison River Basin High/Low graph January 27, 2020 via the NRCS.

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be decreased to 800 cfs on Wednesday, January 29th. Snowpack in the Upper Gunnison Basin is currently at 106% of normal. The Jan 15th runoff forecast for Blue Mesa Reservoir predicts 87% of average for April-July inflows. Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for January through March.

Currently, there are no diversions into the Gunnison Tunnel and flows in the Gunnison River through the Black Canyon are around 1100 cfs. After this release change Gunnison Tunnel diversions will still be at zero and flows in the Gunnison River through the Black Canyon will be around 800 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

This scheduled release change is subject to changes in river flows and weather conditions. For questions or concerns regarding these operations contact Erik Knight at (970) 248-0629 or e-mail at eknight@usbr.gov

Colorado Drought Monitor January 21, 2020.

Montrose: Aspinall Unit operations meeting January 23, 2020 #ColoradoRiver #COriver #aridification

From email from Reclamation (Erik Knight):

The next Aspinall Operations meeting will be on Thursday, January 23rd, at the Holiday Inn Express in Montrose. Start time is 1:00.

Aspinall Unit

Aspinall Unit operations update: Blue Mesa Reservoir within one foot of icing target

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit were decreased to 1100 cfs on Thursday, January 2nd. Blue Mesa Reservoir elevation ended the year within a foot of the icing target. Releases will be maintained at this level for the near future with possible adjustments made when new runoff forecast information becomes available. Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for January through March.

Currently, there are no diversions into the Gunnison Tunnel and flows in the Gunnison River through the Black Canyon are around 1100 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Blue Mesa Reservoir

Aspinall Unit operations update: Blue Mesa releases to be bumped up to meet reservoir icing targets

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be increased to 1600 cfs on Monday, December 9th. Blue Mesa Reservoir elevation remains above the winter icing target level. Releases will be maintained at this level with the goal of lowering the reservoir to the icing target elevation of 7490 feet by December 31st. Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for September through December.

Currently, there are no diversions into the Gunnison Tunnel and flows in the Gunnison River through the Black Canyon are around 1000 cfs. After this release change Gunnison Tunnel diversions will still be at zero and flows in the Gunnison River through the Black Canyon will be around 1600 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall Unit

Aspinall Unit operations update: Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs

Gunnison River Basin. By Shannon1 – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=69257550

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be increased by 200 cfs, today, September 30th. Releases will be decreased by 200 cfs late Friday, October 4th. Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for September through December.

Currently, diversions into the Gunnison Tunnel are 1040 cfs and flows in the Gunnison River through the Black Canyon will increase to 800 cfs today. At the end of this week Gunnison Tunnel diversions will still be 1040 cfs and flows in the Gunnison River through the Black Canyon will return to 600 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall unit operations update: Flows in the Gunnison Tunnel ~= 1030 CFS

Grand opening of the Gunnison Tunnel in Colorado 1909. Photo credit USBR.

From email from Reclamation (Erik Knight):

Releases from the Aspinall Unit will be increased by 100 cfs, today, September 9th. Reservoir contents at Morrow Pt and Crystal have sufficiently recovered to allow for higher releases. Flows in the lower Gunnison River are currently above the baseflow target of 1050 cfs. River flows are expected to stay above the baseflow target for the foreseeable future.

Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for September through December.

Currently, diversions into the Gunnison Tunnel are 1030 cfs and flows in the Gunnison River through the Black Canyon are around 500 cfs. After this release change Gunnison Tunnel diversions will still be 1030 cfs and flows in the Gunnison River through the Black Canyon will be around 600 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Aspinall Unit Operations update: Streamflow in the Black Canyon ~515 cfs

From email from the Bureau of Reclamation (Ryan Christianson):

Releases from the Aspinall Unit will be decreased by 100 cfs at approximately 10am on Tuesday, September 3rd. Pursuant to the Aspinall Unit Operations Record of Decision (ROD), the baseflow target in the lower Gunnison River, as measured at the Whitewater gage, is 1050 cfs for September. This release decrease will allow for the recovery of storage in Crystal Reservoir that was utilized in response to upstream facility outages.

Currently, diversions into the Gunnison Tunnel are approximately 1200 cfs and flows in the Gunnison River through the Black Canyon are around 615 cfs. After this release change, the Gunnison Tunnel diversions will remain near 1200 cfs and flows in the Gunnison River through the Black Canyon will be around 515 cfs. Current flow information is obtained from provisional data that may undergo revision subsequent to review.

Looking downstream from Chasm View, Painted Wall on right. Photo credit: NPS\Lisa Lynch